


Twice the Fun

by sisforsterek



Category: Teen Wolf (TV)
Genre: Anal Sex, Barebacking, Incest, M/M, Threesome, Twincest, Unsafe Sex, set after 3b
Language: English
Status: In-Progress
Published: 2014-04-21
Updated: 2014-04-21
Packaged: 2018-01-20 05:17:16
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,429
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1498039
Author URL: https://archiveofourown.org/users/sisforsterek/pseuds/sisforsterek
Summary: <blockquote class="userstuff">
              <p>Stiles needs a ride to the airport to pick up his twin. Derek's certain Stiles has never told him that he has a twin. He agrees and things get interesting from there.</p>
            </blockquote>





	Twice the Fun

**Author's Note:**

> Regarding the Malia hookup, in this verse, all Stiles and Malia did is what was shown on TV. They made out. Stiles is still technically a virgin.
> 
> I've recently fallen in love with the idea of Stuart as Stiles' twin, so I took a little break from my Sterek mpreg to write this. It will have additional chapters.

"Say that again," Derek says.

"I need a ride to the airport to pick up my brother. My Jeep's in the shop, Dad has to work, and no one else can take me," Stiles says.

"You have a brother," Derek says giving Stiles a disbelieving look.

Stiles nods.

"That you've never mentioned," Derek continues.

"Surely I have," Stiles says.

Derek shakes his head, "You haven't. Trust me. I'd remember."

"So will you take me?" Stiles asks.

Derek nods.

"So how old is your brother?" Derek asks once they're in the car.

"My age. We're identical twins," Stiles replies.

"There's two of you?" Derek says, voice going up in pitch.

"Yep," Stiles replies with a smirk.

Derek groans.

"His name is Stuart," Stiles continues. "He's a computer genius. He developed a program that even I don't understand when he was 14 and Microsoft bought it. He ended up getting into MIT when he was 15 and this is the first time he's been home in two years. Dad and I usually go out to see him every few months, but he decided to take this summer off from college to come home, you know, after what happened."

"Does he know about werewolves then?" Derek asks.

"Yeah, and kanimas and darachs and kitsunes and nogitsunes. I tell him everything. We don't keep secrets," Stiles answers.

"So wait, you get a name that is impossible to pronounce and his name is Stuart?" Derek asks.

Stiles laughs. "I'm firstborn. I got the family name from Mom's grandfather and Stu was named after Dad's side of the family."

"So he's smarter than you, huh?" Derek asks.

"I wouldn't say smarter. He just doesn't have ADD, so he's more focused and has different interests," Stiles answers.

"You always act like your dad is all you have, so I'm just shocked to find out you've got a brother," Derek says.

"That's because I knew Stu was safe at MIT away from this mess," Stiles answers.

"I'm sure there are things that go bump in the night at MIT too," Derek adds.

"But Stu isn't like me. He doesn't go looking for trouble."

"Good to know at least one of you has sense," Derek says.

"Hey!" Stiles protests.

Derek thinks for a minute.

“You don’t have a third bedroom,” Derek says.

“Right,” Stiles agrees.

“So where did Stuart sleep before he left for MIT?” Derek asks.

“You’re really having a hard time wrapping your head around this, aren’t you?” Stiles asks with a laugh.

Derek glares at him.

“My room used to be our room,” Stiles explains.

“But you only have one bed,” Derek points out.

“And you would know, since you seem to love hanging out in my room,” Stiles adds.

“So where does he sleep?” Derek asks when Stiles doesn’t elaborate.

Stiles sighs. “We used to have separate beds, but we’d always end up crawling into each other’s beds after Mom died, so finally dad just got us a double, and we shared a bed for years until he left.”

 

Derek isn't sure what to expect while he sits next to a fidgeting Stiles while waiting for his brother to meet them at baggage claim. Stuart had already texted Stiles when his plane had landed.

Suddenly Stiles jumps out of his seat and runs toward the area with the moving luggage belt. Derek looks up to see him wrap his arms around what is basically his mirror image except for a pair of black rimmed glasses. Stuart hugs Stiles back as Derek gets up to make his way toward them. As he approaches and they finally pull apart, only to have Stiles drape his arm over the back of Stuart's shoulders, Derek can see that Stuart is thinner, more like Stiles was before he started running with werewolves.

Stiles is talking a mile a minute, gesturing with the hand not on Stuart's shoulder, and Stuart is looking at Stiles with obvious affection. Derek can tell they obviously have a closer relationship than many other siblings he's observed.

Finally Stuart looks away from Stiles and glances at Derek.

"You must be Derek," he says. "Stiles has told me quite a bit about you." Then directed at Stiles with a smirk, "I see what you mean."

His voice is slightly deeper than Stiles' but otherwise they even sound alike.

It's messing with Derek's head to see this other version of Stiles. It's like he's never noticed before just how attractive he is. Then immediately he feels guilty. Stiles is a kid!

By the time Stuart has his luggage, Stiles has convinced Derek to take them to a restaurant, because Stuart is hungry and Stiles is always hungry. Derek agrees, not like he had anything important to do today. They end up stopping at TGIF’s and are escorted to a booth. Stiles and Stuart take one side of the booth while Derek slides into the other side.

“So what’s new?” Stiles asks, bumping his shoulder against Stuart.

“Literally nothing since we Skyped this morning,” Stuart replies.

“What? Nothing interesting happened on your trip?” Stiles asks incredulously.

Stuart shakes his head.

“You had your nose in a book all day, didn’t you?” Stiles asks with a laugh.

Stuart shrugs his shoulders, “The graphic novel you gave me for our birthday. I finally have time to read it. I like it.”

Stiles face lights up. “Well at least it’s not a textbook.”

Just then the waitress shows up with their menus and takes their drink orders. They’re mostly silent for a few moments while they decide what they want. As soon as they’ve placed their orders though, Derek can’t hold his curiosity back any longer.

“So what are you majoring in, Stuart?”

“Double major actually. Aerospace engineering and computer science and engineering,” Stuart answers.

“He wants to work for NASA,” Stiles adds, and the look he’s giving Stuart hides nothing. He’s obviously proud of his brother.

“But if that backfires, I’ll be the next Steve Jobs,” Stuart says.

“Steve Jobs? I thought Stiles told me that you sold your program to Microsoft?” Derek says, obviously confused.

“I was fourteen! I’ve learned a lot since then and I’m more of an Apple guy now,” Stuart says with a chuckle.

“You know the difference between Bill Gates and Steve Jobs?” Stiles asks.

“I do watch the news,” Derek says with a laugh.

“Huh.” Stiles says.

“So do you have a girlfriend back at MIT?” Derek asks.

“Uh, I’m gay actually, but I don’t have a boyfriend either,” Stuart answers, glancing at Stiles.

When the food arrives, Stiles and Stuart immediately start stealing food from each other’s plates. Derek knows if anyone else would try that, Stiles would stab them with his fork. He’s seen him do it to Scott before. Halfway through the meal, Stiles even drinks from Stuart’s cup after he empties his own before the waitress has come by to offer a refill. Derek never had that kind of relationship with his siblings, but it still makes his chest ache in the worst way watching the two boys across the table from him laugh and communicate through gestures like they share their own secret language.

Because they’re teenage boys and eat like them, they have to order dessert. Stiles orders the Chocolate Peanut Butter Pie and Stuart orders the Vanilla Bean Cheesecake. Of course they have to share that too. And if that’s not enough, Stuart lets out little sighs of pleasure each time he takes a bite and the moans that slip out of Stiles’ mouth are bordering on obscene. It’s making Derek uncomfortable. Watching two teenagers eat should not be causing the reaction that’s currently going on in his pants. He shifts uncomfortably in the booth.

“Want a bite?” Stiles offers.

“I’m good,” Derek manages to say through gritted teeth.

After he helps carry Stuart’s bags inside the house, he doesn’t see a reason to stick around, so heads back to his car. He pauses upon hearing a thump come from inside the Stilinski house, followed by a gasp, and then a groan. He runs back to the front door and peeks inside the window. What he sees is not what he’s expecting. Although neither twin is in danger, what he’s seeing is still wrong. Stiles is straddling Stuart on the couch and the twins are kissing. Stuart’s hands are tugging at Stiles’ hair and Stiles is grinding down against his twin. Derek backs away in shock.

Derek spends the next few hours back at his loft switching between pacing the floor and sitting on his bed staring at the wall. He can’t get what he saw out of his head. It’s so wrong, but it was really, really turning him on the more he thought about it. He’d never really thought about other men in a sexual way before. He’d been taken advantage of one too many times in the past to really consider sexual relationships in general for the most part. But this was Stiles, someone he trusted. He’d certainly noticed the way Stiles looked at him sometimes, the scent of arousal coming off of him in waves when Derek would push him around sometimes out of frustration and sometimes for his own safety. Derek had refused to think about what that meant. Stiles is a teenager who probably got off on any sort of physical contact.

Before Derek realizes what he’s doing, he’s in his car, driving to Stiles’ house. His dashboard clock reads 11:37PM. He shuts off the engine and takes a deep breath. Stiles will still be awake. It’s summer break. His dad, on the other hand, should be a sleep, so he decides to use his normal entrance, Stiles’ bedroom window. There’s a lamp on in Stiles’ room, and Derek can hear Stiles and Stuart whispering, but he can’t make out the words from where he’s standing in the yard. When he slides the window open, he hears someone gasp out “Who’s there?”

“It’s me,” Derek says as he slides through the window, feet touching down on the floor. When he glances around the room, he notices two sets of eyes staring at him from Stiles’ bed. Stiles and Stuart are staring at him from the bed, both shirtless with the sheet coming up to their waists, their hair sticking every which way and their lips red and swollen. Derek can hear their hearts racing and he can smell the scent of arousal in the air. Derek realizes what he’s just walked in on. His eyes widen.

“Is something wrong?” Stiles finally asks.

“I… I don’t know why I’m here,” Derek admits, eyes darting around the room. “I saw, earlier, when I dropped you off, I heard something, so I came back, and I saw, on the couch…”

“Oh my God,” Stiles moans, turning to rest his head on Stuart’s shoulder.

Stuart seems unaffected. He just stares at Derek for a minute.

“Do you want to join us?” Stuart asks.

"Oh my God," Stiles says again.

"What? He's your wet dream," Stuart whispers.

"Werewolf hearing!" Stiles whispers back.

"Sorry." Stuart says as he rubs his hand along Stiles' back. Then he looks back to Derek, "Well?"

"You're underage," Derek says, clearing his throat.

"Combine our ages and we're 34, totally legal," Stuart says. It’s such a Stiles thing to say.

Stiles snorts and pulls back from Stuart to send Derek a hopeful glance.

Derek nods. He can’t believe he’s giving in this easily, but he knows this is the reason he came here, "How's this going to work?"

"Start by taking your clothes off," Stiles says.

Derek wastes no time stripping, trying not to think about how wrong and illegal this is. Once he's naked, he looks up. Stiles is staring at his cock, completely unashamed. Stuart is leaning against Stiles with his head resting on his shoulder, eyes pointing in the same direction.

"Now get on the bed," Stuart instructs.

Derek takes a step forward, unsure all of the sudden, "I've never been with a guy before."

"It's okay," Stiles says, "we're technically virgins."

"But-" Derek starts.

"We just fool around with each other. We've never went all the way," Stuart explains.

Derek lets out a breath, feeling better knowing at least he doesn't have to live up their previous experiences. He finally sits on the edge of the bed next to Stiles. He looks at Stiles and waits.

“What do you want to do?” Stiles asks shyly.

“What do you want to do?” Derek asks, thrown by the question because Stiles is anything but shy.

“Um,” Stiles starts, but doesn’t actually answer the question, instead he looks at Stuart for some reason.

Stuart lets out a breath and rolls his eyes, “He wants you to fuck him.”

“If you want to,” Stiles adds quickly.

“Ok, yeah,” Derek agrees, then turns to Stuart, “What about you?”

“You can fuck me too after, or if you want, I can fuck you while you’re fucking him. I’m so cool either way,” Stuart replies.

Derek really isn’t sure what is hotter, the shy looks Stiles keeps shooting at him or the confident way that Stuart is telling him what he wants. He’s also never even thought about letting a guy fuck him before, but the idea of fucking Stiles while Stuart fucks into him is just too good to pass up.

“The second option’s good,” Derek says. “So…”

“I can get him ready for you, if you want,” Stuart says, gesturing to Stiles. “I know how he likes it.”

Derek thinks he’s going to blow his load before he even gets his dick in Stiles, but he nods. He watches as Stiles turns over and props himself up on his hands and knees. Stuart finds a bottle of lube that must have been hidden under the sheets. He glances down Stiles back while Stuart coats his fingers, noticing a mole right at the top of his right cheek. Derek wants to bend down and lick it, but he waits. He watches as Stuart spreads Stiles’ cheeks apart and rubs a slick finger around the rim of his hole. Stiles shifts forward slightly on the bed and lets out a whimper. Derek grips the base of his cock to keep from coming at the sound. He watches, trying to memorize every move Stuart makes, so he can do it himself if he gets the chance in the future. He hopes this won’t be a one time thing. He observes how Stuart uses one hand to stroke the curve of Stiles’ spine while he thrusts his fingers into Stiles’ hole with the other hand. He watches as Stiles rocks his hips back to meet the hand. Suddenly Stuart’s hand is on Derek’s cock and he gives it a few strokes before pulling away.

“I think I’m going to have to add another finger, bro,” he says.

And Derek watches him add a fourth finger and waits for Stiles to adjust. Stuart leans down and kisses his shoulder while he waits, then turns to Derek.

“You can touch him, you know,” he says.

Derek had been enjoying watching so much, he kind of forgot he could participate. Now that he’d been reminded, he couldn’t decide what to do first. He reaches out a hand and caresses Stiles’ hip, letting it slide down his leg and rub the inside of his knee. Stiles turns his head and meets his eyes, giving him a soft smile. Then Stuart is back to thrusting his fingers into Stiles’ hole and Derek gets a bit braver. He moves up the bed and leans down to kiss Stiles. At first it’s closed-mouthed, but then Stiles starts to moan and Derek slips his tongue inside. All too soon Stiles pulls away, but he is smiling.

“I’m ready,” he says.

Derek moves back behind Stiles.

“Condom?” Derek asks.

“Well, you can’t get me pregnant, and I know werewolves don’t carry STD’s, so you don’t have to use one,” Stiles says.

“Okay,” Derek says and then Stuarts hand is on his cock again, this time slicking him up with lube.

Then Stuart is pulling his fingers out of Stiles and Stiles lets out this pathetic whimper that has Derek wanting to do whatever he can to make him happy. Stuart is whispering in his ear, telling him to push in slowly, before he’s gone again and then Derek does as he’s told. Derek is about halfway in when he feels the bed shift behind him and Stuart’s hands on his hips. He’d been focusing on not hurting Stiles, so he’s surprised when he hears Stuart say that he’s going to prepare him now. He tries to relax as he feels a finger rub across his hole. He continues to push into Stiles as a slender finger slips into him. It doesn’t hurt, but it’s an unusual feeling. He’d never had the desire to finger himself before, but with the way Stiles seemed to enjoy it, he’s kind of looking forward to the experience. Just as he’s bottoming out into Stiles, Stuart curls his finger inside of him and hits a spot inside of Derek that makes his hips spasm.

“There it is,” Stuart says and slides in another finger. Then Stuart’s whispering in his ear again, “Reach under him and grab his cock, give him a few strokes while he adjusts to you inside of him. He’ll let you know when he’s ready for you to move.”

Derek does as he’s told, but turns his head to whisper back, “How do you know?”

“Porn, dude. Stiles and I watch a lot of porn.”

Stiles says he’s ready just as Stuart’s slipping another finger into Derek. It’s almost too much to focus on all of the sensations, but he tries to tune out what Stuart is doing for the time being to focus on not hurting Stiles. He pulls back slowly and pushes back just as slowly. He does it a few more times before Stiles starts pushing back.

“Yeah,” Stiles says. “Come on.”

Derek takes that as a good sign and moves a little faster. Then he feels Stuart pushing into him. It’s definitely bigger than what his fingers prepared him for, but it’s more uncomfortable than painful, so he keeps his focus on Stiles. Stiles is now uttering a constant string of “Yes, please, come on, Derek, don’t stop.” He’s not shy anymore.

Once Stuart is pushed all the way in, he runs his hands over Derek’s back, waiting for him to adjust. “You can move,” Derek tells him. He’s back to focusing on pounding into Stiles who has started to beg for him to go faster, when Stuart suddenly bites into his shoulder. He had to shift his position to do it, and when he did, he nailed Derek’s prostate. Stuart continues to hit his prostate for the next few thrusts and Derek can feel his orgasm building. He reaches around Stiles to grab his cock again, wanting to make sure he comes before Derek. He doesn’t have to worry, because it only takes a few strokes before Stiles is coming. He bites into his pillow to quiet his screams. Derek follows soon after, practically falling on top of Stiles, barely catching himself to rest on his elbows to avoid crushing the boy.

After a few moments Stiles manages to turn over underneath him, which causes his cock to slip out, and he just grins at Derek. Derek can’t help but smile back and Stiles leans up and catches his lips. Then Stuart is coming and collapsing on top of Derek, not at all worried about crushing him. They stay like that for a few minutes before Stuart slowly pulls out and moves to the side. Stiles turns to look at his brother and smiles. Stuart leans in and kisses him. Derek feels an ache in his chest and he’s not quite sure what it means. After a few more minutes pass with everyone reeling in the afterglow, Derek moves off of Stiles and starts to get dressed. Stiles frowns at him.

“I don’t want to fall asleep here, you know, in case your dad wakes up and finds me in your bed, not a good idea,” Derek tells him.

“Yeah, probably not,” Stiles agrees, still frowning.

“I’ll talk to you tomorrow, though?” Derek says.

Stiles nods as he turns onto his side facing towards Derek. Stuart cuddles up behind him and throws his arm over his chest.

“Love you, Stu.” Derek hears just as he’s closing the window. “Love you too, Stiles.”


End file.
